Multiple partitions may be used for various reasons, such as to
distribute load between different storage pools or technologies.
Please consult Mail Spool Partitions for more details and use cases.

To define additional mail spools, add more "partition-name" entries to
imapd.conf(5) as needed.  For example, let's imagine we want to
migrate users to new partitions split by first character of the user's
last name, and add a partition for shared mailboxes (see Shared
Namespaces):

* Sample:

     defaultpartition: main
     partition-main: /var/spool/imap
     partition-am: /var/spool/imap-am
     partition-nz: /var/spool/imap-nz
     partition-shared: /var/spool/imap-shared
